Agreement of Step-Based Metrics From ActiGraph and ActivPAL Accelerometers Worn Concurrently Among Older Adults

Temporal Associations of Physical Activity With Subsequent Knee Pain in Individuals With Knee Osteoarthritis: An Ecological Momentary Assessment Study

BACKGROUND

Physical activity (PA) is a first-line treatment for knee osteoarthritis and provides benefits for functional improvement and pain relief. However, movement-evoked pain often hinders PA participation and long-term adherence. The relationship between PA and pain is not fully understood and may vary across individuals. We examined the temporal associations between PA and subsequent knee pain in individuals with knee osteoarthritis.

METHODS

In a 10-day ecological momentary assessment (EMA) cohort study, PA was recorded using an Actigraph accelerometer; momentary knee pain intensity was rated on a numeric rating scale in responses to four daily text prompts. Linear mixed-effects models examined within-day and between-day associations between PA and knee pain, adjusting for age, sex and BMI.

RESULTS

The sample included up to 454 observations across 10 days from 17 participants (age = 64 ± 7 years, BMI = 27 ± 4 kg/m2, 61% women), each consisting of a temporal pair of PA minutes and subsequent momentary pain. Within-day, greater moderate-to-vigorous PA (MVPA) minutes were associated with a subsequent increase in knee pain (adjusted β = 0.112, 95% CI: 0.023, 0.201, p = 0.014); while light-intensity PA showed no association with subsequent pain (adjusted β = -0.003, 95% CI: -0.011, 0.005, p = 0.461). Current-day MVPA and light-intensity PA minutes were not associated with next-day knee pain.

CONCLUSIONS

While MVPA may temporarily increase knee pain, its impact was transient. Light-intensity PA showed no association with pain, suggesting it may be a suitable alternative for those with movement-evoked pain. Understanding these temporal patterns can help guide tailored pain management and PA adherence strategies. Further research is needed to confirm these preliminary findings.

SIGNIFICANCE STATEMENT

Understanding the dynamic relationship between PA and knee pain is crucial for optimising the management of knee OA. This exploratory study offers new insights by leveraging high-frequency data to examine the intra- and inter-day associations of MVPA and light-intensity PA with subsequent knee pain. The preliminary findings demonstrate that MVPA may lead to transient pain increases, while light-intensity PA is not associated with pain intensity. Identifying these PA-pain temporal patterns can inform personalised strategies for pain management and improving long-term activity adherence.

Functional Capacity at Rehabilitation Discharge Predicts Physical Activity Characteristics 24 Weeks Later for People With Total Knee Arthroplasty: A Secondary Analysis of a Randomized Controlled Trial

OBJECTIVE

To determine the association between performance-based and patient-reported functional capacity at the conclusion of 12-week rehabilitation with average daily step counts and peak walking cadence 38 weeks after total knee arthroplasty (TKA).

DESIGN

Secondary analysis of a randomized controlled trial.

SETTING

Veterans Affairs Medical Center.

PARTICIPANTS

A total of 87 US military Veterans (age: 67±7y, 87% male).

INTERVENTIONS

Twelve-week rehabilitation beginning 2 weeks post-TKA plus random assignment to either a telehealth-based physical activity behavior change intervention or control group.

MAIN OUTCOME MEASURES

Performance-based (timed Up-and-Go [TUG], 30-second sit-to-stand) and patient-reported measures (Western Ontario and McMaster Universities Osteoarthritis Index, Veterans RAND 12-Item Health Survey [VR-12]) were assessed at rehabilitation discharge (14wk post-TKA). Physical activity was measured using thigh-mounted accelerometry 38 weeks post-TKA. Relationships between participant characteristics (age, sex, body mass index, group assignment), functional capacity at discharge, and long-term physical activity outcomes (average daily step count and peak walking cadence) were evaluated using single- and multiple-variable linear and logistic regressions.

RESULTS

Univariate analyses: TUG time (r=-0.33, P=.002) and VR-12 physical health subscore (r=0.23, P=.036) were correlated with average daily step count at week 38. TUG time (r=-0.31, P=.006) was correlated with peak walking cadence. Multivariate analyses: multiple linear regression controlling for age, sex, and body mass index identified TUG (B=-301.25, P=.039) and VR-12 physical health (B=93.1, P=.049) as predictors of daily step count. TUG time (B=-1.5, P=.012) and assignment to physical activity behavior change intervention (B=13.7, P<.001) predicted peak walking cadence. No significant predictors of attaining a 7500 steps per day threshold were identified.

CONCLUSIONS

Functional capacity at discharge is related to physical activity characteristics 38 weeks post-TKA. Although behavior change interventions are needed to address physical activity deficits postoperatively, the link between functional capacity and activity suggests additional need to address functional capacity limitations during TKA rehabilitation.

Comparison of stepping-based metrics from ActiGraph accelerometers worn concurrently on the non-dominant wrist and waist among young adults

Step counts can be estimated from wrist-worn accelerometers through the Verisense Step Count Algorithm. No study has assessed agreement between stepping metrics from ActiGraph accelerometers during free-living. Thirty-four participants (age: 22.9 ± 3.4 years) provided 24 h accelerometer data (non-dominant wrist) and waist. Agreement of two Verisense Algorithms (Verisense 1 & 2) for estimating daily steps, moderate-to-vigorous physical activity (MVPA), peak 1-min and 30-min accumulated steps, against the waist and ActiLife step-count Algorithm was assessed. Mean bias ± 95% limits of agreement (LoA) for daily steps was +1255 ± 3780 steps/day (mean absolute percent error (MAPE): 21%) (Verisense 1) and +1357 ± 3434 steps/day (MAPE: 20%) (Verisense 2). For peak 1-min accumulated steps, mean bias and 95% LoA was -17 ± 23 steps/min (MAPE: 17%) (Verisense 1) and -6 ± 5 steps/min (MAPE: 9%) with Verisense 2. For peak 30-min accumulated steps, mean bias and 95% LoA was -12 ± 45 steps/min (MAPE: 25%) (Verisense 1) and -2 ± 38 steps/min (MAPE: 13%) (Verisense 2). For MVPA steps/day, mean bias and 95% LoA was -1450 ± 3194 steps/day (MAPE: 420%) (Verisense 1) and -844 ± 2571 steps/day (MAPE: 211%) (Verisense 2). For MVPA min/day, mean bias and 95% LoA was -13 ± 27 min/day (MAPE: 368%) (Verisense 1) and -8 ± 24 min/day (MAPE: 209%) (Verisense 2). The Verisense 2 algorithm enhanced agreement for stepping intensity metrics but further refinement is needed to enhance agreement for MVPA against the waist.

Daily activity patterns in older adults receiving initial support: the association between daily steps and sitting in bouts of at least 60 min

BACKGROUND

Aging has a significant impact on health, underlining the importance of maintaining physical function and reducing time spent sitting among older adults. To understand how to reduce prolonged sitting or increase physical activity, factors related to the daily living and observed daily activity patterns should be explored. This study aimed to investigate the association between daily steps, self-rated health, physical activity, sedentary behavior, motivation to exercise and fear of falling among older adults receiving initial support.

METHOD

Cross-sectional design with total population questionnaire data from adults aged ≥ 60 years (n = 917), living at home with initial support from municipal care in southern Sweden. The older adults were offered to participate in a follow-up study measuring daily activity patterns with accelerometers (n = 72). Linear regression was used to analyze associations between daily steps and possible predictors.

RESULTS

The linear model ([Formula: see text]0.478) showed that sitting in unbroken bouts of > 60 min (β = -0.313, p < 0.05), walking independently outdoors (β = 0.301, p < 0.05), intending to increase physical activity (β = -0.294, p < 0.05), sex (β = 0.279, p < 0.05), relative autonomy index (β = 0.258, p < 0.05), fear of falling (β = -0.238, p < 0.05), and self-rated health (β = 0.213, p < 0.05) predicted daily steps.

CONCLUSION

The model of predictors brings new understanding regarding daily steps among community-dwelling older adults. The association between sitting in bouts of > 60 min and daily steps is interesting as 35% of participants had a number of sitting bouts that on average, showed 30% less steps taken. Minimizing long sitting bouts and maintaining physical functioning to promote independence when walking outdoors can be tools for clinical practitioners devising interventions to break prolonged sitting among community-dwelling older adults. Future research should prioritize studying older adults' outdoor walking independence, including its relation to walking with or without assistive devices and its impact on physical activity and sedentary behavior.